The present invention relates generally to a device housing, and, more particularly, to a housing for an electronic unit or a mechatronic unit. The present invention has particular application in vehicle systems.
Large numbers of housings for electronic and mechatronic units are routinely manufactured, and so they must be capable of being manufactured at a favorable cost. In addition, however, adequate protection of the electronic or mechatronic unit disposed in the housing must also be ensured, especially for service under difficult ambient conditions, such as in motor vehicles. In particular, uncontrolled ingress of water into the housing must be prevented. For this purpose, the housing is typically equipped with an encircling, statically designed, elastic seal, which seals a top part against a bottom part of the housing in the assembled condition.
Furthermore, it is advantageous for the housing to be capable of controlled air exchange with the surrounding atmosphere (“breathing”). This serves to prevent condensation from forming in the interior of the housing under fluctuating ambient temperatures. In mechatronic units, which may operate with injection of compressed air into the housing, this also serves to prevent potentially harmful overpressure in the housing.
DE 19704532 A1 as well as EP 0772959 B1 describe watertight housings composed of a top part and a bottom part, wherein the two parts in assembled condition are sealed against one another by an encircling seal. This arrangement prevents the ingress of dirty water into the housing. However, conventional housings for electronic and mechatronic units do not have any openings to atmosphere that permit a breathing process.
DE 10022124 A1 describes a housing for a control unit, especially a mechatronic unit, which is provided with a pressure-relief bore for venting or admitting air. This arrangement prevents condensation from forming in the housing and also maintains the pressure in the interior space at atmospheric pressure. This arrangement also prevents a pressure rise in the interior space of the housing in the event of a leak from a compressed-air supply to a pressure sensor. The housing described in DE 10022124 A1, however, suffers from the disadvantage that dirty water can reach the interior space through the bore. As a result, sensitive components can be damaged.
Accordingly, it is desired to provide a device housing, especially for an electronic unit or a mechatronic unit, that protects against the ingress of dirty water and, at the same time, permits rapid pressure relief to atmosphere in the event of an overpressure condition in the housing.